Heat exchanger



H. W. HOW

HEAT-EXCHANGE}? Jime 7, 1932.

Filed Sept. 5, 1930 actors of reference indicate like parts in the Patented June 7; 1932 UNITED STATES PATENT OFFICE HARLAN W. HOW, OI WARREN, PENNSYLVANIA, SSIGNOR TO- STRUTEERS WELLS- TITU'SVILLE CORPORATION, 015 WARREN, PE

DELAWARE SYL'VANIA, A CORPORATION OF mas-r nxcmnenn Application filed September 5, 1930. Serial No. 479,954.

This invention relates to a heat exchanger which is more particularly designed for exchanging heat between one fluid and another,

as for example from a hot liquid or gaseous medium to a cooler liquid or gaseous medium.

One of the objects of this invention is to so organize the apparatus that one of the-tube sheets is mounted so that the same is free to move to and fro and compensate for any expansion or contraction without liability of any fluid in one current leaking into the fluid of the other current.

Another object of this invention is. to so' mount the tube cluster, and tube sheets so that the joints between the tubes and sheets can be observed while being tested for determining leakage at such oints.

A further object of this invention is to provide improved. means for mounting the tube cluster and its sheets in the enclosing shell 'so that the tube cluster and sheets can be read- Fig. 3 is a vertical transverse section taken on line 33, Fig. 1, looking toward the'left or rear end of the apparatus.

Fig. is a similar section taken on line, 44, Fig. 1, but looking toward the front or right end of the apparatus.

Fig. 5 isa fragmentary tion showing a modified form of the means for securing the rear head of the apparatus to the floating tube sheet.

In the following description similar charseveral figures of the drawing:

The numeral 10 represents the tubular shell, body or casing of the apparatus which is preferably arranged horizontally and constructed of sheet metal. Adjacent to its front or right hand end this shell is provided with an inlet 11 and an outlet 12-for one of the fluid mediums which is to exchange heat, said inlet and outlet having preferably the form of tu.-

longitudinal secbular necks which connect with the upper and lower parts of the shell-so that the same are on diametrically opposite sides thereof, as shown in Figs. 1 and 4. At its front end the shell has, secured to its exterior by welding or otherwise an annular attaching collar flange or ring 13, the outer face of which is rovidd with an annular recess or rabbet 14. 11 its rear end the shell has secured to its exterior an annular attaching collar, flange or rin 15 having an internal counterbore 16. Wit in the shell is arranged a cluster or bundle of parallel heat exchange tubes, pipes or flues which in the present case are divided into an upper set 17 of rearward conducting tubes, an intermediate set of forward conducting tubes 171, an intermediate set 181 of rearward conducting tubes, and a lower set of forward conducting tubes 18. ends of these tubes are seeuredin any suitable manner in a-plurality of openings 19 in a front tube sheet or plate 20 arranged adjacent to the front end of the shell, and the rear ends of these tubes are secured in any suitable manner in a plurality of openings 21 The numeral 23 represents the body of a front manifold which is preferably of cylindrical form and made of cast metal and has an inlet 24 and an outlet 25 for the other fluid medium with which heat is to be exchanged, said inlet and outlet having prgf erably the form of tubular necks which connect with the upper and lower parts of the front manifold body and communicate with diametrically opposite sides of the. same, as shown in Fig. 1. On its rear end face the front manifold body is provided with an annular recess or rabbet 26 which is arranged opposite the rabbet 14 of the front attaching ring 13, and on its front end the front manifold body is provided with an annular recess or rabbet 27. The front tube sheet 20 has its edge arranged between the front shell ring 13 and therear edge-0f the front manifold body and a leaktight joint ,is formed rear sides of the marginal part of the front tube sheet and the corresponding rabbets l4 and 26 of the front shell attaching ring and the rear end of the front manifold body, and a plurality of fastening bolts 30 connecting said front attaching ring and the front manifold body outside of said rabbets, as shown in Figs. 1, 2 and 4. By this means the front tube sheet 20 is held in a fixed position rela tive to the shell 10 and the front manifold body and the front ends of the tubes are likewise held in a fixed or immovable position during the operation of the apparatus. Within the front manifold body two horizontal partitions 31, 32 are arranged one above the other and extend from the front end to the rear end thereof so as to form upper, intermediate and lower connecting chambers 33, 34, within this manifold body. The rear edge of upper partition 31 is arranged between the upper rearwardly conducting set of tubes 17 and the upper intermediate forwardly conducting set'of tubes 171 and a leaktight joint is formed between the rear edge of this upper partition and the adjacent part of the front tube sheet 20 by a packing strip 36, and the rear edge of the lower partition 32 is arranged between the lower intermediate rearwardly conducting set of tubes 181 and the lower forwardly conducting set of tubes 18 and a leaktight joint is formed between the rear edge of this lower partition and the adjacent part of the front tube sheet 2Ov by a packing strip 37, as shown in Figs. 1 and 2. The front ends of the connecting chambers 33, 34, 35 of the manifold body are closed by a detachable frbnt cover 38 which is detachably secured atits edge to the front end of the front manifold body by means of bolts 39 and is provided on its inner side with upper and lower partition ribs 40, 41 arranged horizontal and opposite the front ends of the upper and lower partitions 31, 32 of the front manifold body. A leaktight joint is formed betweenthe front cover 38 and the front manifoldbody by a gasket or packing 42 interposed between the annular recess or rabbet 27 in the front end of the front manifold body and the inner side of the marginal part of the front cover, and packing strips 44 interposed between the frontedges of the partitions 31, 32 and the inner edges of the partition ribs 40, 41 as shown in Figs. 1 and 2,

The rear tube sheet 22 is mounted on the rear end of the shell so that the same-is free to move lengthwise thereof in response to the temperature changes in the tubes which cause the latter to expand and contract ]ength wise, this mounting being so constructedthat such movement is possible without permitwhich slides in the rear end of the shell 10 and the rear attaching ring or collar 15. In the annular cavity or pocket which is thus produced around the joint sleeve 45 by the bore 16 in the collar 15, a packing 46 is arranged and this packing is pressed into this pocket by an annular gland 47 engaging its inner end with said packing and connected at its outer end with the rear attaching collar 15 by tightening bolts 48, as shown in Figs. 1 and 2.

In rear of the rear tube sheet is arranged a rear cover 49 which is detachably connected at its edge with the marginal part of the rear tube sheet and its joint sleeve and which is provided on its inner side with a horizontal partition 50 arranged opposite the rear side of therear tube sheet between the upper intermediate set of tubes 171 and the lower intermediate set of tubes 181 and forming a manifold containing upper and lower connecting chambers 51,, 52. A leaktight joint is formed between the rear cover 49 and the rear tube sheet by an annular packing 53 between the rear side of the marginal part of the rear tube sheet and an annular rabbet or recess 54 on the inner side of the rear cover and a packing strip 55 inter-' posed between the rear side of the rear tube sheet and the inner edge of the rear partition rib50.

Although the rear manifold cover 49 may be detachably connected with the rear .tube sheet in various ways that shown in Figs. 1, 12 and 3 is preferable and constructed as folows:

The numeral 56 represents an annularv membering this ring and the rear tube sheetand oint sleeve. In front of this anchor ring 18 arranged a complete or non-split draw or backing ring 59 which surrounds the joint sleeve and is provided on its rear side with an annular. recess or rabbet 60 which receives the outer edge portion of the anchor ring sections and bears against the front side of the same.

The draw ring and the rear caver 49 are detachably connected by bolts 61 passing through the draw ring and the anchor ring sections and also through the marginal part of the rear cover, as shown in Figs. 1 and 2. If desired,-bolts 62 may be employed for connecting the draw ring and the rear cover which are arranged outside of the anchor ring and do not pass through the latter, as show'n upper intermediate set of tubes 171 and the lower intermediate set of tubes 181 a main baffle 62'having the form of metal plate which terminates at its rear end short of the rear tube sheet so as to form a gap or passage 63 therebetween while the front end of'this plate is connected by a welded joint 64 or otherwise with the rearside of the front tube sheet simply removing the bolts 61, when access and the oppositelongitudinal edges 65 of this plate are fitted close to the diametrically opposite sides of the interior of the shell, as

shown in Figs. 1 and 4.

By means of this baifle the interior of the shell is divided into upper and lower longitudinal passages 66, 67 which connect at their front ends with the inlet 11 and outlet 12, and the upper passage containing the tubes 17, 171 and the lower passage the tubes 18, 181.

In the operation of this apparatus the current of the fluid to be heated and the current of the fluid to be cooled may either be run counterwise in opposite directions or the same may be run parallel in the same direction and it is also possible to run either one of these fluids through the inner side of the heat exchange tubes and the other along the outer side of the same.

Assuming that the necks 11 and 12 are the inlet and outlet for the hot fluid and the necks 24 and 25 the inlet and outlet for the relatively cool fluid, respectively, the cool fluid passes from the inlet 24 successively through the upper front connecting chamber 33, rear- Wardly through the upper tubes 17, downwardly through the upper rear connecting chamber 51, forwardly through the upper intermediate tubes 171, downwardly through the front intermediate connecting chamber 34, rearwardly through the'loWer intermediate tubes 181, downwardly through the lower. rear connecting chamber 52, forwardly through tubes 18, and downwardly through the lower front connecting chamber 35 to the outlet 25. At-the same time the relatively hot fltiid passes successively from the inletll rearwardly through the upper longitudinal passage 66-and along the exterior of the tubes 17, 171, thence downwardly through the gap 63 and thence forwardly through the lower longitudinal passage 67 and along the'exterior-of the tubes 18, 181 to the outlet 12. During theparallel movement of the cold and hot fluid along the interior and exterior of the tubes the heat in the hot fluid is transferred to the cold fluid, this operation continuingso long as hot and cold fluids traverse these conduits in the manner described. As the tubes expand and contract due to the changes in the temperature of the fluids which are being circulated the joint sleeve 45 slides in the stuffing box which latter is formed on the rear end of the shell by the collar 15, packing 16 and gland 47. A tight joint is thus maintained between the rear tube sheet 22 and the shell 10 for preventing the escape of any fluid from the shell and also preventing any fluid passing from the shell to the rear manifold, and

vice versa. Leakage from one of these conduits to the other and mixing of the fluids passing through the respective conduits is thus positively prevented.

Removal of the rear cover 22 is possible by to the rear ends of the tubes is necessary, but when the entire tube bundle must be removed from the shell for any reason, this can be i done through the front end by detaching the front manifold body and also by detaching the rear manifold cover 49, split anchor ring 57 and the'draw ring 60. To permit the removal of the anchor ring the draw rin is first moved forwardly so that the same oes .additional obstructions are arranged in the path of the fluid traversing the upper and lower longitudinal passages in the shell so asto compel the respective fluid to follow a tortuous or zig-zag path and thus transfer more of its heat-to the other fluid. This is accomplished in the present case by employing sets of baflles in the upper and lower longitudinal passages 66, 67, each set consisting preferably of inner auxiliary balfles 68, and@ outer auxiliary bafiies 69 which alternate with each other; and upper and lower sets of retaining rods 70, 71 for supporting said auxiliary baffles in the upper and lower passages" 66, 67 and maintaining the same in the desired position relative'to each other and the main baffle and the shell. The auxiliary baffles are constructed of metal plates which are arranged transversely in the respective passagesand engage loosely inner edges from the main bafiles by intervening inner gaps 72 and inner auxiliary baffles 68 are separatedat their outer edges from the. inner side of the shell by intervening outer gaps 73, these outer and inner gaps alternating and'causing the fluid to take a tortuous course through the respective longitudinal passage, as shown by the arrows in Fig. 1. These auxiliary baflles are provided with openings for the "passages of the respec tive heat exchange tubes and alsowith openings for receiving the retaining rods 70, 71.

The inner auxiliary baflies are preferably connected with the main bafile by welded joints 74-and the retaining rods are preferably connected by welded joints 75 with the respective auxiliary battles and alsoconnected at their front ends by welded joints 76 with the front tube sheet, thereby forming practically an integral structure with the main baffle, front tube sheet and tubes so that the same may be placed in and removed from the shell as a unit.

One of the principal advantages in this construction is that the same eliminates the possibility of leakage from one fluid to another, this being highly important, for example, when heating or cooling a light product such as gasoline by a heavier product like crude oil or lubricating oil, inasmuch as leakage of crude oil or lubricating oil into gasoline would discolor the latter and impair its values WVhen water and oil are circulated leakage of water into the oil is also detrimental to the quality of the latter.

Another advantage lies in the fact that either end of the tubes is readily accessible for inspection or repairs by removing only one cover. In the constructions of heat exchangers heretofore known'which contain'a movable or floating tube sheet or plate it has been necessary to take off two covers to gain access to the floating ends of the tubes.

The improved means for detachably mounting the rear coverat the floating end of the heat exchanging tubes particularly the draw or backing ring in connection with the anchor ring, renders it convenient to in- 7 spect and repair this end of the tubes when required.

By taking off the frontmanifold body, the rear cover and its fastening the entire bundle of tubes, tube sheets, and baffles can be removed as a unit from the shell-at the front end of the latter and also assembled in like manner. I

A further decided advantage inherent in this construction is due to the possibility-of testing the tubes by fluid pressure without any difficulty because this can be done by merely removing the front and rear covers and applying fluid pressure within the shell. A'ny leaks due to tube failure at either end of the same will be plainly visible, this being a great advantage over prior structures which cannot be conveniently and easily tested to ascertain which tube is leaking.

I claim as my invention:

1. A heat exchanger, comprising a shell having a fluid inlet and a fluid outlet, a front tube sheet connected with the front end of the shell, a stuffing box arranged on t e rear end of the shell, a rear tubesheet havinga forwardly projecting sleeve which slides in said stufiing box, a single bundle of tubes arranged in said shell and secured at their front and rear ends to said front and rear tube sheets, a front manifold connected with the front tube sheet and communicating with-the front ends of said tubes and having a fluid inlet and a fluid outlet, a rear manifold connected with the rear tube sheet and communicating with the rear ends of said tubes, and

a detachable cover applied to the outer side of said rear manifold externally of said shell.

2. A heat exchanger, comprising a shell having a fluid inlet and a fluid outlet, a front tube sheet connected with the front end of said shell, a rear tube sheet slidable lengthwise on the rear end of said shell and forming a leaktight joint therewith, a single bundle of tubes arranged in said shell and connected with said front and rear sheets, acover extending across the rear ends of said tubes externally of the shell, and means for detachab-ly connecting said-rear tube sheet and said cover. i

3. A heat exchanger, comprising a shell having a fluid inlet and a fluid outlet, a front tube sheet connected with the front end of said shell, a rear tube sheet slidable lengthwise on the rear end of said shell and forming a leaktight joint therewith, tubes arranged in said shell and connected with said front and rear sheets, a cover extending across the rear ends of said tubes, means for detachably connecting said rear tube sheet and said cover, and comprising an external groove on said rear tube sheet, a sectional anchor engaging said groove, a draw member engaging the inner side of said anchor, and fastening bolts connecting said draw member and said cover.

4,. A heat exchanger, comprising a shell having a fluid inlet and a fluid outlet, a front tube sheet connected with the front end of I said shell, a rear tube sheet slidable lengt across the rear ends of said tubes, means for detachably connecting said rear tube sheet and said cover, and comprising an external groove on said rear tube sheet, a sectional anchor engaging said groove, a draw member engaging the inner side of said anchor, and fastening bolts connectingfsaid draw member and said cover and passing through said anchor.

5. A heat exchanger, comprising a shell provided with a fluid inlet and a fluid outlet, a front tube sheet connected with the front end of said shell, a rear tube sheet slidably connected with the rear end of "said shell and forming a leaktight joint therewith and havin an annular external groove, tubes arranged in said shell and connected with said front and rear tube sheets, a rear cover extending across the rear ends of said tubes and engaging said rear tube sheet, a sectional anchor engaging said groove, a draw ring surrounding said rear tube sheet and provided on its rear side with an annular rabbet tea.

which receives said sectional anchor, and v 6. A heat exchanger, comprising a shell provided with a fluid inlet and a fluid outlet, a front tube sheet connected with the front end of said shell, a rear tube sheet slidably connect-ed with the rear end of said shell and forming a leaktight joint therewith and having an annular external groove, tubes arranged in said shell and connected with said front and rear tube sheets, a rear cover extending across the rear ends of said tubes and engaging said rear tube sheet, a sectional anchor engaging said groove a draw ring surrounding said rear tube s eet and provided on its rear side with an annular rabbet which receives said sectional anchor, and fastening bolts connecting said draw rin and rear tube sheet and arranged outside 0 said sectional anchor.

- In testimony whereof I hereby afiix my signature.

HARLAN W. HOW. I 

